Flexible electric heater.



'A. E. GRAPP.

FLEXIBLE ELECTRIC HEATER.

APPLICATION FILED DEC .20I I915.

Patented Feb. 26,1918.

UNITED STATES PATENT OFFICE.-

ALBERT a. sun, or nnmmonls, MINNESOTA, ASSIG-NOB r0 nnsra'rcn MANUFAC- some 00., or MINNEAPOLIS, MINNESOTA, A CORPORATION or MINNESOTA.

FLEXIBLE ELECTRIC HEATER.

Specification of better: Patent. Patented Feb. 26, 1918.

Application fled December 20, 1915. Serial No. 67,779.

To all whom it may concern:

Be it known that I, ALBERT. E. GRAPP, a c1t 1zen of the United States, residing at Minneapolis, in the county of Hennepin and State of Minnesota, have invented certain new and useful Improvements in Flexible Electric Heaters; and I do hereby declare the following to be a full, clear, and exact description of the invention, suchaswill enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an extremel simple and hi hly efli'cient portable an flexible electrica heater especially adapted for use for warming up various parts of an internal combustion en e such as used in automobiles, but capab e of more general use.

To the above ends, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

In the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings, I

Figure 1 is a plan view with some parts broken away showingthe improvedheater;

Fig. 2 is a section taken on the line :12 w of Flg. 1; and

Fig. 3 is a fragmentary section on the line w as of Fi- 1.

The flexible body or casing 1 of the heater is in the form of a flattened flexible tube a that is woven from asbestos am or similar respective contact ins 5.

non-combustible material. ne end of the tube 1 is slipped over an'elongated, or flat head 2 that is made from asbestos board, or other hard and tou h material that is a nonconductorof electricity. An elo ted metallic clampin collar 3 is placed around that end of, the to e 1 which is telescoped-over the said head 2 and is clamped thereto and to the said head t or bolts 4. Circuit contacts in the form of pins 5 are passed through the head 2 in parallel arrangement,,and are clampe to the said heads b nuts 6 and 7. The nuts 7 clamp the on s of the heatin element to the he said heating element 8is in the cm of a coiled wire that is bent into a zigza parallel formation and between the para el y small nut-equipped screws portions of the sai 85 spring, the intermediateportion of the flattened tube 1 is united b longitudinal rows of stitches 9 that shoul be formed" also by the use of asbestos yarn. The stitches 9 keep the, folds or runs properly spaced apart, so that they cannot be short-circuited by contact. A"coiled wire or conductor'8, of, course has great flexibility, and, in fact, has as great flexibility as the casing 1, itself. The other endv of the tube'l has its edge folded in, as best indicated at 10 in Figs. 1 and 2, and the outer portions of these folds are held together by stitches 11, also of asbestos yarn. These folds project beyond the adjacent portions of'the heating wire 8,.and, as they are of a non-conducting material, they will never become very hot, and'hence, can always be held in the hand, so that' the flexible heater may be properly positioned or applied to or around a device or part to be heated. The other end of the heater may be held by taking hold of the clamping collar 3, for that element is not in the electric circuit, nor has it direct contact with the heating element. However, the current will usually be supplied through conductors inclosed-in a cable 12 having a head 13 of insulating material, such as vulcanized rubber or wood fiber, and provided within with contacts adapted to engage with the contact pins 5 when the said head is forced frictionally onto the said phis. The construclarly stated, this heater is adapted for many other uses, such, for example, as heating rectifier bulbs for storage batteries, or for thawing out frozen water pipes.

What I claim is:

1. In a flexible electrical heater, the combination with a flexible tube of noncombustible material, of a coiled heating wire bent into a tortuous form and contained within saidtube, an elongated head of insulating material inserted into one end of said tube,

tion of the said head 13 is well known, and

a clam in collar surrounding the same end of sai tu e and provided with means for clamping the same onto said head, and circuit connections a plied to and head and thereby insulated om each other, the ends of said heating wire being attached, one to each of said contacts.

2. In a flexible electrical heater, the combination with a flexible tube of noncombustible material, of a coiled heatin wire bent into zigzag arallel form an contained within said tu e, the said tube being stitched between the parallel portions of said coiled wire to form com artments therefor, an elongated rigid hea of insulating material inserted into the end of sald tube, a clam in collar surrounding the same end ofsaid tu e and provided with means for clamping the same onto said head, and circuit contacts applied to the said head and thereb insu- 15 lated from each other, the ends'of said coiled wire bein attached, one to each of said contacts, t e other end of said tube being turned inward upon itself and stitched toether forming a relatively cool electricall 2O ln'sulated portion beyond said heating coil:

In testimony whereof I affix my signature 2 in presence of two witnesses.

ALBERT E. GRAPP. Witnesses:

HARRY D. Kimonn, F. D. MERCHANT. 

